1. Field of the Invention
The invention relates to a method and a device for non-invasively measuring the blood pressure of a patient.
2. Description of Related Art
Automatic electronic blood pressure monitors for non-invasively measuring the blood pressures are widely known. Such monitors determine the value of the systolic and the diastolic blood pressure e.g. on the basis of an oscillometric measurement. During such a measurement, the pressure within an inflated cuff wrapped around the arm of a patient is measured during deflation of the cuff. The systolic and the diastolic blood pressure and optionally the pulse rate are determined on the basis of the variation of the cuff pressure.
Automatic, electronic blood pressure measuring devices are usually applied to the upper arm of a patient, around the wrist or to a finger of the patient. There are always specific causes for errors during such measurements. Inaccurate measurement results may be due to normal physiological changes, insufficient rest condition of the patient, to pathologic blood pressure changes or to technical or application related artifact. For example application artifact may be caused by movements of the application site during the measurement cycle. The errors created by insufficient rest condition and by motion artifact could be avoided if the patient correctly follows the user instructions of such a measuring device. It is, however, often the case, that measurements are carried out with the patient being not at a sufficient rest condition or patient application sites are moving during the measurement. This may lead to incorrect measurement results.
This problem has already been addressed in the copending European patent application EP-99122743.9 of the same inventors.